bin/ed/main.c

   1 /* main.c: This file contains the main control and user-interface routines
   2    for the ed line editor. */
   3 /*-
   4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * @(#) Copyright (c) 1993 Andrew Moore, Talke Studio. All rights reserved.
  29  * @(#)main.c,v 1.1 1994/02/01 00:34:42 alm Exp
  30  * $FreeBSD: head/bin/ed/main.c 241720 2012-10-19 05:43:38Z ed $
  31  */
  32
  33 /*
  34  * CREDITS
  35  *
  36  *      This program is based on the editor algorithm described in
  37  *      Brian W. Kernighan and P. J. Plauger's book "Software Tools
  38  *      in Pascal," Addison-Wesley, 1981.
  39  *
  40  *      The buffering algorithm is attributed to Rodney Ruddock of
  41  *      the University of Guelph, Guelph, Ontario.
  42  *
  43  *      The cbc.c encryption code is adapted from
  44  *      the bdes program by Matt Bishop of Dartmouth College,
  45  *      Hanover, NH.
  46  *
  47  */
  48
  49 #include <sys/types.h>
  50
  51 #include <sys/ioctl.h>
  52 #include <sys/wait.h>
  53 #include <ctype.h>
  54 #include <locale.h>
  55 #include <pwd.h>
  56 #include <setjmp.h>
  57
  58 #include "ed.h"
  59
  60
  61 #ifdef _POSIX_SOURCE
  62 static sigjmp_buf env;
  63 #else
  64 static jmp_buf env;
  65 #endif
  66
  67 /* static buffers */
  68 char stdinbuf[1];               /* stdin buffer */
  69 static char *shcmd;             /* shell command buffer */
  70 static int shcmdsz;             /* shell command buffer size */
  71 static int shcmdi;              /* shell command buffer index */
  72 char *ibuf;                     /* ed command-line buffer */
  73 int ibufsz;                     /* ed command-line buffer size */
  74 char *ibufp;                    /* pointer to ed command-line buffer */
  75
  76 /* global flags */
  77 int des = 0;                    /* if set, use crypt(3) for i/o */
  78 static int garrulous = 0;       /* if set, print all error messages */
  79 int isbinary;                   /* if set, buffer contains ASCII NULs */
  80 int isglobal;                   /* if set, doing a global command */
  81 int modified;                   /* if set, buffer modified since last write */
  82 int mutex = 0;                  /* if set, signals set "sigflags" */
  83 static int red = 0;             /* if set, restrict shell/directory access */
  84 int scripted = 0;               /* if set, suppress diagnostics */
  85 int sigflags = 0;               /* if set, signals received while mutex set */
  86 static int sigactive = 0;       /* if set, signal handlers are enabled */
  87
  88 static char old_filename[PATH_MAX] = ""; /* default filename */
  89 long current_addr;              /* current address in editor buffer */
  90 long addr_last;                 /* last address in editor buffer */
  91 int lineno;                     /* script line number */
  92 static const char *prompt;      /* command-line prompt */
  93 static const char *dps = "*";   /* default command-line prompt */
  94
  95 static const char *usage = "usage: %s [-] [-sx] [-p string] [file]\n";
  96
  97 /* ed: line editor */
  98 int
  99 main(volatile int argc, char ** volatile argv)
 100 {
 101         int c, n;
 102         long status = 0;
 103
 104         setlocale(LC_ALL, "");
 105
 106         red = (n = strlen(argv[0])) > 2 && argv[0][n - 3] == 'r';
 107 top:
 108         while ((c = getopt(argc, argv, "p:sx")) != -1)
 109                 switch(c) {
 110                 case 'p':                               /* set prompt */
 111                         prompt = optarg;
 112                         break;
 113                 case 's':                               /* run script */
 114                         scripted = 1;
 115                         break;
 116                 case 'x':                               /* use crypt */
 117 #ifdef DES
 118                         des = get_keyword();
 119 #else
 120                         fprintf(stderr, "crypt unavailable\n?\n");
 121 #endif
 122                         break;
 123
 124                 default:
 125                         fprintf(stderr, usage, red ? "red" : "ed");
 126                         exit(1);
 127                 }
 128         argv += optind;
 129         argc -= optind;
 130         if (argc && **argv == '-') {
 131                 scripted = 1;
 132                 if (argc > 1) {
 133                         optind = 1;
 134                         goto top;
 135                 }
 136                 argv++;
 137                 argc--;
 138         }
 139         /* assert: reliable signals! */
 140 #ifdef SIGWINCH
 141         handle_winch(SIGWINCH);
 142         if (isatty(0)) signal(SIGWINCH, handle_winch);
 143 #endif
 144         signal(SIGHUP, signal_hup);
 145         signal(SIGQUIT, SIG_IGN);
 146         signal(SIGINT, signal_int);
 147 #ifdef _POSIX_SOURCE
 148         if ((status = sigsetjmp(env, 1)))
 149 #else
 150         if ((status = setjmp(env)))
 151 #endif
 152         {
 153                 fputs("\n?\n", stderr);
 154                 errmsg = "interrupt";
 155         } else {
 156                 init_buffers();
 157                 sigactive = 1;                  /* enable signal handlers */
 158                 if (argc && **argv && is_legal_filename(*argv)) {
 159                         if (read_file(*argv, 0) < 0 && !isatty(0))
 160                                 quit(2);
 161                         else if (**argv != '!')
 162                                 if (strlcpy(old_filename, *argv, sizeof(old_filename))
 163                                     >= sizeof(old_filename))
 164                                         quit(2);
 165                 } else if (argc) {
 166                         fputs("?\n", stderr);
 167                         if (**argv == '\0')
 168                                 errmsg = "invalid filename";
 169                         if (!isatty(0))
 170                                 quit(2);
 171                 }
 172         }
 173         for (;;) {
 174                 if (status < 0 && garrulous)
 175                         fprintf(stderr, "%s\n", errmsg);
 176                 if (prompt) {
 177                         printf("%s", prompt);
 178                         fflush(stdout);
 179                 }
 180                 if ((n = get_tty_line()) < 0) {
 181                         status = ERR;
 182                         continue;
 183                 } else if (n == 0) {
 184                         if (modified && !scripted) {
 185                                 fputs("?\n", stderr);
 186                                 errmsg = "warning: file modified";
 187                                 if (!isatty(0)) {
 188                                         if (garrulous)
 189                                                 fprintf(stderr,
 190                                                     "script, line %d: %s\n",
 191                                                     lineno, errmsg);
 192                                         quit(2);
 193                                 }
 194                                 clearerr(stdin);
 195                                 modified = 0;
 196                                 status = EMOD;
 197                                 continue;
 198                         } else
 199                                 quit(0);
 200                 } else if (ibuf[n - 1] != '\n') {
 201                         /* discard line */
 202                         errmsg = "unexpected end-of-file";
 203                         clearerr(stdin);
 204                         status = ERR;
 205                         continue;
 206                 }
 207                 isglobal = 0;
 208                 if ((status = extract_addr_range()) >= 0 &&
 209                     (status = exec_command()) >= 0)
 210                         if (!status ||
 211                             (status = display_lines(current_addr, current_addr,
 212                                 status)) >= 0)
 213                                 continue;
 214                 switch (status) {
 215                 case EOF:
 216                         quit(0);
 217                 case EMOD:
 218                         modified = 0;
 219                         fputs("?\n", stderr);           /* give warning */
 220                         errmsg = "warning: file modified";
 221                         if (!isatty(0)) {
 222                                 if (garrulous)
 223                                         fprintf(stderr, "script, line %d: %s\n",
 224                                             lineno, errmsg);
 225                                 quit(2);
 226                         }
 227                         break;
 228                 case FATAL:
 229                         if (!isatty(0)) {
 230                                 if (garrulous)
 231                                         fprintf(stderr, "script, line %d: %s\n",
 232                                             lineno, errmsg);
 233                         } else if (garrulous)
 234                                 fprintf(stderr, "%s\n", errmsg);
 235                         quit(3);
 236                 default:
 237                         fputs("?\n", stderr);
 238                         if (!isatty(0)) {
 239                                 if (garrulous)
 240                                         fprintf(stderr, "script, line %d: %s\n",
 241                                             lineno, errmsg);
 242                                 quit(2);
 243                         }
 244                         break;
 245                 }
 246         }
 247         /*NOTREACHED*/
 248 }
 249
 250 long first_addr, second_addr;
 251 static long addr_cnt;
 252
 253 /* extract_addr_range: get line addresses from the command buffer until an
 254    illegal address is seen; return status */
 255 int
 256 extract_addr_range(void)
 257 {
 258         long addr;
 259
 260         addr_cnt = 0;
 261         first_addr = second_addr = current_addr;
 262         while ((addr = next_addr()) >= 0) {
 263                 addr_cnt++;
 264                 first_addr = second_addr;
 265                 second_addr = addr;
 266                 if (*ibufp != ',' && *ibufp != ';')
 267                         break;
 268                 else if (*ibufp++ == ';')
 269                         current_addr = addr;
 270         }
 271         if ((addr_cnt = min(addr_cnt, 2)) == 1 || second_addr != addr)
 272                 first_addr = second_addr;
 273         return (addr == ERR) ? ERR : 0;
 274 }
 275
 276
 277 #define SKIP_BLANKS() while (isspace((unsigned char)*ibufp) && *ibufp != '\n') ibufp++
 278
 279 #define MUST_BE_FIRST() do {                                    \
 280         if (!first) {                                           \
 281                 errmsg = "invalid address";                     \
 282                 return ERR;                                     \
 283         }                                                       \
 284 } while (0)
 285
 286 /*  next_addr: return the next line address in the command buffer */
 287 long
 288 next_addr(void)
 289 {
 290         const char *hd;
 291         long addr = current_addr;
 292         long n;
 293         int first = 1;
 294         int c;
 295
 296         SKIP_BLANKS();
 297         for (hd = ibufp;; first = 0)
 298                 switch (c = *ibufp) {
 299                 case '+':
 300                 case '\t':
 301                 case ' ':
 302                 case '-':
 303                 case '^':
 304                         ibufp++;
 305                         SKIP_BLANKS();
 306                         if (isdigit((unsigned char)*ibufp)) {
 307                                 STRTOL(n, ibufp);
 308                                 addr += (c == '-' || c == '^') ? -n : n;
 309                         } else if (!isspace((unsigned char)c))
 310                                 addr += (c == '-' || c == '^') ? -1 : 1;
 311                         break;
 312                 case '0': case '1': case '2':
 313                 case '3': case '4': case '5':
 314                 case '6': case '7': case '8': case '9':
 315                         MUST_BE_FIRST();
 316                         STRTOL(addr, ibufp);
 317                         break;
 318                 case '.':
 319                 case '$':
 320                         MUST_BE_FIRST();
 321                         ibufp++;
 322                         addr = (c == '.') ? current_addr : addr_last;
 323                         break;
 324                 case '/':
 325                 case '?':
 326                         MUST_BE_FIRST();
 327                         if ((addr = get_matching_node_addr(
 328                             get_compiled_pattern(), c == '/')) < 0)
 329                                 return ERR;
 330                         else if (c == *ibufp)
 331                                 ibufp++;
 332                         break;
 333                 case '\'':
 334                         MUST_BE_FIRST();
 335                         ibufp++;
 336                         if ((addr = get_marked_node_addr(*ibufp++)) < 0)
 337                                 return ERR;
 338                         break;
 339                 case '%':
 340                 case ',':
 341                 case ';':
 342                         if (first) {
 343                                 ibufp++;
 344                                 addr_cnt++;
 345                                 second_addr = (c == ';') ? current_addr : 1;
 346                                 addr = addr_last;
 347                                 break;
 348                         }
 349                         /* FALLTHROUGH */
 350                 default:
 351                         if (ibufp == hd)
 352                                 return EOF;
 353                         else if (addr < 0 || addr_last < addr) {
 354                                 errmsg = "invalid address";
 355                                 return ERR;
 356                         } else
 357                                 return addr;
 358                 }
 359         /* NOTREACHED */
 360 }
 361
 362
 363 #ifdef BACKWARDS
 364 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 365 #define GET_THIRD_ADDR(addr) \
 366 { \
 367         long ol1, ol2; \
 368 \
 369         ol1 = first_addr, ol2 = second_addr; \
 370         if (extract_addr_range() < 0) \
 371                 return ERR; \
 372         else if (addr_cnt == 0) { \
 373                 errmsg = "destination expected"; \
 374                 return ERR; \
 375         } else if (second_addr < 0 || addr_last < second_addr) { \
 376                 errmsg = "invalid address"; \
 377                 return ERR; \
 378         } \
 379         addr = second_addr; \
 380         first_addr = ol1, second_addr = ol2; \
 381 }
 382 #else   /* BACKWARDS */
 383 /* GET_THIRD_ADDR: get a legal address from the command buffer */
 384 #define GET_THIRD_ADDR(addr) \
 385 { \
 386         long ol1, ol2; \
 387 \
 388         ol1 = first_addr, ol2 = second_addr; \
 389         if (extract_addr_range() < 0) \
 390                 return ERR; \
 391         if (second_addr < 0 || addr_last < second_addr) { \
 392                 errmsg = "invalid address"; \
 393                 return ERR; \
 394         } \
 395         addr = second_addr; \
 396         first_addr = ol1, second_addr = ol2; \
 397 }
 398 #endif
 399
 400
 401 /* GET_COMMAND_SUFFIX: verify the command suffix in the command buffer */
 402 #define GET_COMMAND_SUFFIX() { \
 403         int done = 0; \
 404         do { \
 405                 switch(*ibufp) { \
 406                 case 'p': \
 407                         gflag |= GPR, ibufp++; \
 408                         break; \
 409                 case 'l': \
 410                         gflag |= GLS, ibufp++; \
 411                         break; \
 412                 case 'n': \
 413                         gflag |= GNP, ibufp++; \
 414                         break; \
 415                 default: \
 416                         done++; \
 417                 } \
 418         } while (!done); \
 419         if (*ibufp++ != '\n') { \
 420                 errmsg = "invalid command suffix"; \
 421                 return ERR; \
 422         } \
 423 }
 424
 425
 426 /* sflags */
 427 #define SGG 001         /* complement previous global substitute suffix */
 428 #define SGP 002         /* complement previous print suffix */
 429 #define SGR 004         /* use last regex instead of last pat */
 430 #define SGF 010         /* repeat last substitution */
 431
 432 int patlock = 0;        /* if set, pattern not freed by get_compiled_pattern() */
 433
 434 long rows = 22;         /* scroll length: ws_row - 2 */
 435
 436 /* exec_command: execute the next command in command buffer; return print
 437    request, if any */
 438 int
 439 exec_command(void)
 440 {
 441         static pattern_t *pat = NULL;
 442         static int sgflag = 0;
 443         static long sgnum = 0;
 444
 445         pattern_t *tpat;
 446         char *fnp;
 447         int gflag = 0;
 448         int sflags = 0;
 449         long addr = 0;
 450         int n = 0;
 451         int c;
 452
 453         SKIP_BLANKS();
 454         switch(c = *ibufp++) {
 455         case 'a':
 456                 GET_COMMAND_SUFFIX();
 457                 if (!isglobal) clear_undo_stack();
 458                 if (append_lines(second_addr) < 0)
 459                         return ERR;
 460                 break;
 461         case 'c':
 462                 if (check_addr_range(current_addr, current_addr) < 0)
 463                         return ERR;
 464                 GET_COMMAND_SUFFIX();
 465                 if (!isglobal) clear_undo_stack();
 466                 if (delete_lines(first_addr, second_addr) < 0 ||
 467                     append_lines(current_addr) < 0)
 468                         return ERR;
 469                 break;
 470         case 'd':
 471                 if (check_addr_range(current_addr, current_addr) < 0)
 472                         return ERR;
 473                 GET_COMMAND_SUFFIX();
 474                 if (!isglobal) clear_undo_stack();
 475                 if (delete_lines(first_addr, second_addr) < 0)
 476                         return ERR;
 477                 else if ((addr = INC_MOD(current_addr, addr_last)) != 0)
 478                         current_addr = addr;
 479                 break;
 480         case 'e':
 481                 if (modified && !scripted)
 482                         return EMOD;
 483                 /* FALLTHROUGH */
 484         case 'E':
 485                 if (addr_cnt > 0) {
 486                         errmsg = "unexpected address";
 487                         return ERR;
 488                 } else if (!isspace((unsigned char)*ibufp)) {
 489                         errmsg = "unexpected command suffix";
 490                         return ERR;
 491                 } else if ((fnp = get_filename()) == NULL)
 492                         return ERR;
 493                 GET_COMMAND_SUFFIX();
 494                 if (delete_lines(1, addr_last) < 0)
 495                         return ERR;
 496                 clear_undo_stack();
 497                 if (close_sbuf() < 0)
 498                         return ERR;
 499                 else if (open_sbuf() < 0)
 500                         return FATAL;
 501                 if (*fnp && *fnp != '!') strcpy(old_filename, fnp);
 502 #ifdef BACKWARDS
 503                 if (*fnp == '\0' && *old_filename == '\0') {
 504                         errmsg = "no current filename";
 505                         return ERR;
 506                 }
 507 #endif
 508                 if (read_file(*fnp ? fnp : old_filename, 0) < 0)
 509                         return ERR;
 510                 clear_undo_stack();
 511                 modified = 0;
 512                 u_current_addr = u_addr_last = -1;
 513                 break;
 514         case 'f':
 515                 if (addr_cnt > 0) {
 516                         errmsg = "unexpected address";
 517                         return ERR;
 518                 } else if (!isspace((unsigned char)*ibufp)) {
 519                         errmsg = "unexpected command suffix";
 520                         return ERR;
 521                 } else if ((fnp = get_filename()) == NULL)
 522                         return ERR;
 523                 else if (*fnp == '!') {
 524                         errmsg = "invalid redirection";
 525                         return ERR;
 526                 }
 527                 GET_COMMAND_SUFFIX();
 528                 if (*fnp) strcpy(old_filename, fnp);
 529                 printf("%s\n", strip_escapes(old_filename));
 530                 break;
 531         case 'g':
 532         case 'v':
 533         case 'G':
 534         case 'V':
 535                 if (isglobal) {
 536                         errmsg = "cannot nest global commands";
 537                         return ERR;
 538                 } else if (check_addr_range(1, addr_last) < 0)
 539                         return ERR;
 540                 else if (build_active_list(c == 'g' || c == 'G') < 0)
 541                         return ERR;
 542                 else if ((n = (c == 'G' || c == 'V')))
 543                         GET_COMMAND_SUFFIX();
 544                 isglobal++;
 545                 if (exec_global(n, gflag) < 0)
 546                         return ERR;
 547                 break;
 548         case 'h':
 549                 if (addr_cnt > 0) {
 550                         errmsg = "unexpected address";
 551                         return ERR;
 552                 }
 553                 GET_COMMAND_SUFFIX();
 554                 if (*errmsg) fprintf(stderr, "%s\n", errmsg);
 555                 break;
 556         case 'H':
 557                 if (addr_cnt > 0) {
 558                         errmsg = "unexpected address";
 559                         return ERR;
 560                 }
 561                 GET_COMMAND_SUFFIX();
 562                 if ((garrulous = 1 - garrulous) && *errmsg)
 563                         fprintf(stderr, "%s\n", errmsg);
 564                 break;
 565         case 'i':
 566                 if (second_addr == 0) {
 567                         errmsg = "invalid address";
 568                         return ERR;
 569                 }
 570                 GET_COMMAND_SUFFIX();
 571                 if (!isglobal) clear_undo_stack();
 572                 if (append_lines(second_addr - 1) < 0)
 573                         return ERR;
 574                 break;
 575         case 'j':
 576                 if (check_addr_range(current_addr, current_addr + 1) < 0)
 577                         return ERR;
 578                 GET_COMMAND_SUFFIX();
 579                 if (!isglobal) clear_undo_stack();
 580                 if (first_addr != second_addr &&
 581                     join_lines(first_addr, second_addr) < 0)
 582                         return ERR;
 583                 break;
 584         case 'k':
 585                 c = *ibufp++;
 586                 if (second_addr == 0) {
 587                         errmsg = "invalid address";
 588                         return ERR;
 589                 }
 590                 GET_COMMAND_SUFFIX();
 591                 if (mark_line_node(get_addressed_line_node(second_addr), c) < 0)
 592                         return ERR;
 593                 break;
 594         case 'l':
 595                 if (check_addr_range(current_addr, current_addr) < 0)
 596                         return ERR;
 597                 GET_COMMAND_SUFFIX();
 598                 if (display_lines(first_addr, second_addr, gflag | GLS) < 0)
 599                         return ERR;
 600                 gflag = 0;
 601                 break;
 602         case 'm':
 603                 if (check_addr_range(current_addr, current_addr) < 0)
 604                         return ERR;
 605                 GET_THIRD_ADDR(addr);
 606                 if (first_addr <= addr && addr < second_addr) {
 607                         errmsg = "invalid destination";
 608                         return ERR;
 609                 }
 610                 GET_COMMAND_SUFFIX();
 611                 if (!isglobal) clear_undo_stack();
 612                 if (move_lines(addr) < 0)
 613                         return ERR;
 614                 break;
 615         case 'n':
 616                 if (check_addr_range(current_addr, current_addr) < 0)
 617                         return ERR;
 618                 GET_COMMAND_SUFFIX();
 619                 if (display_lines(first_addr, second_addr, gflag | GNP) < 0)
 620                         return ERR;
 621                 gflag = 0;
 622                 break;
 623         case 'p':
 624                 if (check_addr_range(current_addr, current_addr) < 0)
 625                         return ERR;
 626                 GET_COMMAND_SUFFIX();
 627                 if (display_lines(first_addr, second_addr, gflag | GPR) < 0)
 628                         return ERR;
 629                 gflag = 0;
 630                 break;
 631         case 'P':
 632                 if (addr_cnt > 0) {
 633                         errmsg = "unexpected address";
 634                         return ERR;
 635                 }
 636                 GET_COMMAND_SUFFIX();
 637                 prompt = prompt ? NULL : optarg ? optarg : dps;
 638                 break;
 639         case 'q':
 640         case 'Q':
 641                 if (addr_cnt > 0) {
 642                         errmsg = "unexpected address";
 643                         return ERR;
 644                 }
 645                 GET_COMMAND_SUFFIX();
 646                 gflag =  (modified && !scripted && c == 'q') ? EMOD : EOF;
 647                 break;
 648         case 'r':
 649                 if (!isspace((unsigned char)*ibufp)) {
 650                         errmsg = "unexpected command suffix";
 651                         return ERR;
 652                 } else if (addr_cnt == 0)
 653                         second_addr = addr_last;
 654                 if ((fnp = get_filename()) == NULL)
 655                         return ERR;
 656                 GET_COMMAND_SUFFIX();
 657                 if (!isglobal) clear_undo_stack();
 658                 if (*old_filename == '\0' && *fnp != '!')
 659                         strcpy(old_filename, fnp);
 660 #ifdef BACKWARDS
 661                 if (*fnp == '\0' && *old_filename == '\0') {
 662                         errmsg = "no current filename";
 663                         return ERR;
 664                 }
 665 #endif
 666                 if ((addr = read_file(*fnp ? fnp : old_filename, second_addr)) < 0)
 667                         return ERR;
 668                 else if (addr && addr != addr_last)
 669                         modified = 1;
 670                 break;
 671         case 's':
 672                 do {
 673                         switch(*ibufp) {
 674                         case '\n':
 675                                 sflags |=SGF;
 676                                 break;
 677                         case 'g':
 678                                 sflags |= SGG;
 679                                 ibufp++;
 680                                 break;
 681                         case 'p':
 682                                 sflags |= SGP;
 683                                 ibufp++;
 684                                 break;
 685                         case 'r':
 686                                 sflags |= SGR;
 687                                 ibufp++;
 688                                 break;
 689                         case '0': case '1': case '2': case '3': case '4':
 690                         case '5': case '6': case '7': case '8': case '9':
 691                                 STRTOL(sgnum, ibufp);
 692                                 sflags |= SGF;
 693                                 sgflag &= ~GSG;         /* override GSG */
 694                                 break;
 695                         default:
 696                                 if (sflags) {
 697                                         errmsg = "invalid command suffix";
 698                                         return ERR;
 699                                 }
 700                         }
 701                 } while (sflags && *ibufp != '\n');
 702                 if (sflags && !pat) {
 703                         errmsg = "no previous substitution";
 704                         return ERR;
 705                 } else if (sflags & SGG)
 706                         sgnum = 0;              /* override numeric arg */
 707                 if (*ibufp != '\n' && *(ibufp + 1) == '\n') {
 708                         errmsg = "invalid pattern delimiter";
 709                         return ERR;
 710                 }
 711                 tpat = pat;
 712                 SPL1();
 713                 if ((!sflags || (sflags & SGR)) &&
 714                     (tpat = get_compiled_pattern()) == NULL) {
 715                         SPL0();
 716                         return ERR;
 717                 } else if (tpat != pat) {
 718                         if (pat) {
 719                                 regfree(pat);
 720                                 free(pat);
 721                         }
 722                         pat = tpat;
 723                         patlock = 1;            /* reserve pattern */
 724                 }
 725                 SPL0();
 726                 if (!sflags && extract_subst_tail(&sgflag, &sgnum) < 0)
 727                         return ERR;
 728                 else if (isglobal)
 729                         sgflag |= GLB;
 730                 else
 731                         sgflag &= ~GLB;
 732                 if (sflags & SGG)
 733                         sgflag ^= GSG;
 734                 if (sflags & SGP)
 735                         sgflag ^= GPR, sgflag &= ~(GLS | GNP);
 736                 do {
 737                         switch(*ibufp) {
 738                         case 'p':
 739                                 sgflag |= GPR, ibufp++;
 740                                 break;
 741                         case 'l':
 742                                 sgflag |= GLS, ibufp++;
 743                                 break;
 744                         case 'n':
 745                                 sgflag |= GNP, ibufp++;
 746                                 break;
 747                         default:
 748                                 n++;
 749                         }
 750                 } while (!n);
 751                 if (check_addr_range(current_addr, current_addr) < 0)
 752                         return ERR;
 753                 GET_COMMAND_SUFFIX();
 754                 if (!isglobal) clear_undo_stack();
 755                 if (search_and_replace(pat, sgflag, sgnum) < 0)
 756                         return ERR;
 757                 break;
 758         case 't':
 759                 if (check_addr_range(current_addr, current_addr) < 0)
 760                         return ERR;
 761                 GET_THIRD_ADDR(addr);
 762                 GET_COMMAND_SUFFIX();
 763                 if (!isglobal) clear_undo_stack();
 764                 if (copy_lines(addr) < 0)
 765                         return ERR;
 766                 break;
 767         case 'u':
 768                 if (addr_cnt > 0) {
 769                         errmsg = "unexpected address";
 770                         return ERR;
 771                 }
 772                 GET_COMMAND_SUFFIX();
 773                 if (pop_undo_stack() < 0)
 774                         return ERR;
 775                 break;
 776         case 'w':
 777         case 'W':
 778                 if ((n = *ibufp) == 'q' || n == 'Q') {
 779                         gflag = EOF;
 780                         ibufp++;
 781                 }
 782                 if (!isspace((unsigned char)*ibufp)) {
 783                         errmsg = "unexpected command suffix";
 784                         return ERR;
 785                 } else if ((fnp = get_filename()) == NULL)
 786                         return ERR;
 787                 if (addr_cnt == 0 && !addr_last)
 788                         first_addr = second_addr = 0;
 789                 else if (check_addr_range(1, addr_last) < 0)
 790                         return ERR;
 791                 GET_COMMAND_SUFFIX();
 792                 if (*old_filename == '\0' && *fnp != '!')
 793                         strcpy(old_filename, fnp);
 794 #ifdef BACKWARDS
 795                 if (*fnp == '\0' && *old_filename == '\0') {
 796                         errmsg = "no current filename";
 797                         return ERR;
 798                 }
 799 #endif
 800                 if ((addr = write_file(*fnp ? fnp : old_filename,
 801                     (c == 'W') ? "a" : "w", first_addr, second_addr)) < 0)
 802                         return ERR;
 803                 else if (addr == addr_last)
 804                         modified = 0;
 805                 else if (modified && !scripted && n == 'q')
 806                         gflag = EMOD;
 807                 break;
 808         case 'x':
 809                 if (addr_cnt > 0) {
 810                         errmsg = "unexpected address";
 811                         return ERR;
 812                 }
 813                 GET_COMMAND_SUFFIX();
 814 #ifdef DES
 815                 des = get_keyword();
 816                 break;
 817 #else
 818                 errmsg = "crypt unavailable";
 819                 return ERR;
 820 #endif
 821         case 'z':
 822 #ifdef BACKWARDS
 823                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0)
 824 #else
 825                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0)
 826 #endif
 827                         return ERR;
 828                 else if ('0' < *ibufp && *ibufp <= '9')
 829                         STRTOL(rows, ibufp);
 830                 GET_COMMAND_SUFFIX();
 831                 if (display_lines(second_addr, min(addr_last,
 832                     second_addr + rows), gflag) < 0)
 833                         return ERR;
 834                 gflag = 0;
 835                 break;
 836         case '=':
 837                 GET_COMMAND_SUFFIX();
 838                 printf("%ld\n", addr_cnt ? second_addr : addr_last);
 839                 break;
 840         case '!':
 841                 if (addr_cnt > 0) {
 842                         errmsg = "unexpected address";
 843                         return ERR;
 844                 } else if ((sflags = get_shell_command()) < 0)
 845                         return ERR;
 846                 GET_COMMAND_SUFFIX();
 847                 if (sflags) printf("%s\n", shcmd + 1);
 848                 system(shcmd + 1);
 849                 if (!scripted) printf("!\n");
 850                 break;
 851         case '\n':
 852 #ifdef BACKWARDS
 853                 if (check_addr_range(first_addr = 1, current_addr + 1) < 0
 854 #else
 855                 if (check_addr_range(first_addr = 1, current_addr + !isglobal) < 0
 856 #endif
 857                  || display_lines(second_addr, second_addr, 0) < 0)
 858                         return ERR;
 859                 break;
 860         default:
 861                 errmsg = "unknown command";
 862                 return ERR;
 863         }
 864         return gflag;
 865 }
 866
 867
 868 /* check_addr_range: return status of address range check */
 869 int
 870 check_addr_range(long n, long m)
 871 {
 872         if (addr_cnt == 0) {
 873                 first_addr = n;
 874                 second_addr = m;
 875         }
 876         if (first_addr > second_addr || 1 > first_addr ||
 877             second_addr > addr_last) {
 878                 errmsg = "invalid address";
 879                 return ERR;
 880         }
 881         return 0;
 882 }
 883
 884
 885 /* get_matching_node_addr: return the address of the next line matching a
 886    pattern in a given direction.  wrap around begin/end of editor buffer if
 887    necessary */
 888 long
 889 get_matching_node_addr(pattern_t *pat, int dir)
 890 {
 891         char *s;
 892         long n = current_addr;
 893         line_t *lp;
 894
 895         if (!pat) return ERR;
 896         do {
 897                if ((n = dir ? INC_MOD(n, addr_last) : DEC_MOD(n, addr_last))) {
 898                         lp = get_addressed_line_node(n);
 899                         if ((s = get_sbuf_line(lp)) == NULL)
 900                                 return ERR;
 901                         if (isbinary)
 902                                 NUL_TO_NEWLINE(s, lp->len);
 903                         if (!regexec(pat, s, 0, NULL, 0))
 904                                 return n;
 905                }
 906         } while (n != current_addr);
 907         errmsg = "no match";
 908         return  ERR;
 909 }
 910
 911
 912 /* get_filename: return pointer to copy of filename in the command buffer */
 913 char *
 914 get_filename(void)
 915 {
 916         static char *file = NULL;
 917         static int filesz = 0;
 918
 919         int n;
 920
 921         if (*ibufp != '\n') {
 922                 SKIP_BLANKS();
 923                 if (*ibufp == '\n') {
 924                         errmsg = "invalid filename";
 925                         return NULL;
 926                 } else if ((ibufp = get_extended_line(&n, 1)) == NULL)
 927                         return NULL;
 928                 else if (*ibufp == '!') {
 929                         ibufp++;
 930                         if ((n = get_shell_command()) < 0)
 931                                 return NULL;
 932                         if (n)
 933                                 printf("%s\n", shcmd + 1);
 934                         return shcmd;
 935                 } else if (n > PATH_MAX - 1) {
 936                         errmsg = "filename too long";
 937                         return  NULL;
 938                 }
 939         }
 940 #ifndef BACKWARDS
 941         else if (*old_filename == '\0') {
 942                 errmsg = "no current filename";
 943                 return  NULL;
 944         }
 945 #endif
 946         REALLOC(file, filesz, PATH_MAX, NULL);
 947         for (n = 0; *ibufp != '\n';)
 948                 file[n++] = *ibufp++;
 949         file[n] = '\0';
 950         return is_legal_filename(file) ? file : NULL;
 951 }
 952
 953
 954 /* get_shell_command: read a shell command from stdin; return substitution
 955    status */
 956 int
 957 get_shell_command(void)
 958 {
 959         static char *buf = NULL;
 960         static int n = 0;
 961
 962         char *s;                        /* substitution char pointer */
 963         int i = 0;
 964         int j = 0;
 965
 966         if (red) {
 967                 errmsg = "shell access restricted";
 968                 return ERR;
 969         } else if ((s = ibufp = get_extended_line(&j, 1)) == NULL)
 970                 return ERR;
 971         REALLOC(buf, n, j + 1, ERR);
 972         buf[i++] = '!';                 /* prefix command w/ bang */
 973         while (*ibufp != '\n')
 974                 switch (*ibufp) {
 975                 default:
 976                         REALLOC(buf, n, i + 2, ERR);
 977                         buf[i++] = *ibufp;
 978                         if (*ibufp++ == '\\')
 979                                 buf[i++] = *ibufp++;
 980                         break;
 981                 case '!':
 982                         if (s != ibufp) {
 983                                 REALLOC(buf, n, i + 1, ERR);
 984                                 buf[i++] = *ibufp++;
 985                         }
 986 #ifdef BACKWARDS
 987                         else if (shcmd == NULL || *(shcmd + 1) == '\0')
 988 #else
 989                         else if (shcmd == NULL)
 990 #endif
 991                         {
 992                                 errmsg = "no previous command";
 993                                 return ERR;
 994                         } else {
 995                                 REALLOC(buf, n, i + shcmdi, ERR);
 996                                 for (s = shcmd + 1; s < shcmd + shcmdi;)
 997                                         buf[i++] = *s++;
 998                                 s = ibufp++;
 999                         }
1000                         break;
1001                 case '%':
1002                         if (*old_filename  == '\0') {
1003                                 errmsg = "no current filename";
1004                                 return ERR;
1005                         }
1006                         j = strlen(s = strip_escapes(old_filename));
1007                         REALLOC(buf, n, i + j, ERR);
1008                         while (j--)
1009                                 buf[i++] = *s++;
1010                         s = ibufp++;
1011                         break;
1012                 }
1013         REALLOC(shcmd, shcmdsz, i + 1, ERR);
1014         memcpy(shcmd, buf, i);
1015         shcmd[shcmdi = i] = '\0';
1016         return *s == '!' || *s == '%';
1017 }
1018
1019
1020 /* append_lines: insert text from stdin to after line n; stop when either a
1021    single period is read or EOF; return status */
1022 int
1023 append_lines(long n)
1024 {
1025         int l;
1026         const char *lp = ibuf;
1027         const char *eot;
1028         undo_t *up = NULL;
1029
1030         for (current_addr = n;;) {
1031                 if (!isglobal) {
1032                         if ((l = get_tty_line()) < 0)
1033                                 return ERR;
1034                         else if (l == 0 || ibuf[l - 1] != '\n') {
1035                                 clearerr(stdin);
1036                                 return  l ? EOF : 0;
1037                         }
1038                         lp = ibuf;
1039                 } else if (*(lp = ibufp) == '\0')
1040                         return 0;
1041                 else {
1042                         while (*ibufp++ != '\n')
1043                                 ;
1044                         l = ibufp - lp;
1045                 }
1046                 if (l == 2 && lp[0] == '.' && lp[1] == '\n') {
1047                         return 0;
1048                 }
1049                 eot = lp + l;
1050                 SPL1();
1051                 do {
1052                         if ((lp = put_sbuf_line(lp)) == NULL) {
1053                                 SPL0();
1054                                 return ERR;
1055                         } else if (up)
1056                                 up->t = get_addressed_line_node(current_addr);
1057                         else if ((up = push_undo_stack(UADD, current_addr,
1058                             current_addr)) == NULL) {
1059                                 SPL0();
1060                                 return ERR;
1061                         }
1062                 } while (lp != eot);
1063                 modified = 1;
1064                 SPL0();
1065         }
1066         /* NOTREACHED */
1067 }
1068
1069
1070 /* join_lines: replace a range of lines with the joined text of those lines */
1071 int
1072 join_lines(long from, long to)
1073 {
1074         static char *buf = NULL;
1075         static int n;
1076
1077         char *s;
1078         int size = 0;
1079         line_t *bp, *ep;
1080
1081         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1082         bp = get_addressed_line_node(from);
1083         for (; bp != ep; bp = bp->q_forw) {
1084                 if ((s = get_sbuf_line(bp)) == NULL)
1085                         return ERR;
1086                 REALLOC(buf, n, size + bp->len, ERR);
1087                 memcpy(buf + size, s, bp->len);
1088                 size += bp->len;
1089         }
1090         REALLOC(buf, n, size + 2, ERR);
1091         memcpy(buf + size, "\n", 2);
1092         if (delete_lines(from, to) < 0)
1093                 return ERR;
1094         current_addr = from - 1;
1095         SPL1();
1096         if (put_sbuf_line(buf) == NULL ||
1097             push_undo_stack(UADD, current_addr, current_addr) == NULL) {
1098                 SPL0();
1099                 return ERR;
1100         }
1101         modified = 1;
1102         SPL0();
1103         return 0;
1104 }
1105
1106
1107 /* move_lines: move a range of lines */
1108 int
1109 move_lines(long addr)
1110 {
1111         line_t *b1, *a1, *b2, *a2;
1112         long n = INC_MOD(second_addr, addr_last);
1113         long p = first_addr - 1;
1114         int done = (addr == first_addr - 1 || addr == second_addr);
1115
1116         SPL1();
1117         if (done) {
1118                 a2 = get_addressed_line_node(n);
1119                 b2 = get_addressed_line_node(p);
1120                 current_addr = second_addr;
1121         } else if (push_undo_stack(UMOV, p, n) == NULL ||
1122             push_undo_stack(UMOV, addr, INC_MOD(addr, addr_last)) == NULL) {
1123                 SPL0();
1124                 return ERR;
1125         } else {
1126                 a1 = get_addressed_line_node(n);
1127                 if (addr < first_addr) {
1128                         b1 = get_addressed_line_node(p);
1129                         b2 = get_addressed_line_node(addr);
1130                                         /* this get_addressed_line_node last! */
1131                 } else {
1132                         b2 = get_addressed_line_node(addr);
1133                         b1 = get_addressed_line_node(p);
1134                                         /* this get_addressed_line_node last! */
1135                 }
1136                 a2 = b2->q_forw;
1137                 REQUE(b2, b1->q_forw);
1138                 REQUE(a1->q_back, a2);
1139                 REQUE(b1, a1);
1140                 current_addr = addr + ((addr < first_addr) ?
1141                     second_addr - first_addr + 1 : 0);
1142         }
1143         if (isglobal)
1144                 unset_active_nodes(b2->q_forw, a2);
1145         modified = 1;
1146         SPL0();
1147         return 0;
1148 }
1149
1150
1151 /* copy_lines: copy a range of lines; return status */
1152 int
1153 copy_lines(long addr)
1154 {
1155         line_t *lp, *np = get_addressed_line_node(first_addr);
1156         undo_t *up = NULL;
1157         long n = second_addr - first_addr + 1;
1158         long m = 0;
1159
1160         current_addr = addr;
1161         if (first_addr <= addr && addr < second_addr) {
1162                 n =  addr - first_addr + 1;
1163                 m = second_addr - addr;
1164         }
1165         for (; n > 0; n=m, m=0, np = get_addressed_line_node(current_addr + 1))
1166                 for (; n-- > 0; np = np->q_forw) {
1167                         SPL1();
1168                         if ((lp = dup_line_node(np)) == NULL) {
1169                                 SPL0();
1170                                 return ERR;
1171                         }
1172                         add_line_node(lp);
1173                         if (up)
1174                                 up->t = lp;
1175                         else if ((up = push_undo_stack(UADD, current_addr,
1176                             current_addr)) == NULL) {
1177                                 SPL0();
1178                                 return ERR;
1179                         }
1180                         modified = 1;
1181                         SPL0();
1182                 }
1183         return 0;
1184 }
1185
1186
1187 /* delete_lines: delete a range of lines */
1188 int
1189 delete_lines(long from, long to)
1190 {
1191         line_t *n, *p;
1192
1193         SPL1();
1194         if (push_undo_stack(UDEL, from, to) == NULL) {
1195                 SPL0();
1196                 return ERR;
1197         }
1198         n = get_addressed_line_node(INC_MOD(to, addr_last));
1199         p = get_addressed_line_node(from - 1);
1200                                         /* this get_addressed_line_node last! */
1201         if (isglobal)
1202                 unset_active_nodes(p->q_forw, n);
1203         REQUE(p, n);
1204         addr_last -= to - from + 1;
1205         current_addr = from - 1;
1206         modified = 1;
1207         SPL0();
1208         return 0;
1209 }
1210
1211
1212 /* display_lines: print a range of lines to stdout */
1213 int
1214 display_lines(long from, long to, int gflag)
1215 {
1216         line_t *bp;
1217         line_t *ep;
1218         char *s;
1219
1220         if (!from) {
1221                 errmsg = "invalid address";
1222                 return ERR;
1223         }
1224         ep = get_addressed_line_node(INC_MOD(to, addr_last));
1225         bp = get_addressed_line_node(from);
1226         for (; bp != ep; bp = bp->q_forw) {
1227                 if ((s = get_sbuf_line(bp)) == NULL)
1228                         return ERR;
1229                 if (put_tty_line(s, bp->len, current_addr = from++, gflag) < 0)
1230                         return ERR;
1231         }
1232         return 0;
1233 }
1234
1235
1236 #define MAXMARK 26                      /* max number of marks */
1237
1238 static line_t *mark[MAXMARK];           /* line markers */
1239 static int markno;                      /* line marker count */
1240
1241 /* mark_line_node: set a line node mark */
1242 int
1243 mark_line_node(line_t *lp, int n)
1244 {
1245         if (!islower((unsigned char)n)) {
1246                 errmsg = "invalid mark character";
1247                 return ERR;
1248         } else if (mark[n - 'a'] == NULL)
1249                 markno++;
1250         mark[n - 'a'] = lp;
1251         return 0;
1252 }
1253
1254
1255 /* get_marked_node_addr: return address of a marked line */
1256 long
1257 get_marked_node_addr(int n)
1258 {
1259         if (!islower((unsigned char)n)) {
1260                 errmsg = "invalid mark character";
1261                 return ERR;
1262         }
1263         return get_line_node_addr(mark[n - 'a']);
1264 }
1265
1266
1267 /* unmark_line_node: clear line node mark */
1268 void
1269 unmark_line_node(line_t *lp)
1270 {
1271         int i;
1272
1273         for (i = 0; markno && i < MAXMARK; i++)
1274                 if (mark[i] == lp) {
1275                         mark[i] = NULL;
1276                         markno--;
1277                 }
1278 }
1279
1280
1281 /* dup_line_node: return a pointer to a copy of a line node */
1282 line_t *
1283 dup_line_node(line_t *lp)
1284 {
1285         line_t *np;
1286
1287         if ((np = (line_t *) malloc(sizeof(line_t))) == NULL) {
1288                 fprintf(stderr, "%s\n", strerror(errno));
1289                 errmsg = "out of memory";
1290                 return NULL;
1291         }
1292         np->seek = lp->seek;
1293         np->len = lp->len;
1294         return np;
1295 }
1296
1297
1298 /* has_trailing_escape:  return the parity of escapes preceding a character
1299    in a string */
1300 int
1301 has_trailing_escape(char *s, char *t)
1302 {
1303     return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);
1304 }
1305
1306
1307 /* strip_escapes: return copy of escaped string of at most length PATH_MAX */
1308 char *
1309 strip_escapes(char *s)
1310 {
1311         static char *file = NULL;
1312         static int filesz = 0;
1313
1314         int i = 0;
1315
1316         REALLOC(file, filesz, PATH_MAX, NULL);
1317         while (i < filesz - 1   /* Worry about a possible trailing escape */
1318                && (file[i++] = (*s == '\\') ? *++s : *s))
1319                 s++;
1320         return file;
1321 }
1322
1323
1324 void
1325 signal_hup(int signo)
1326 {
1327         if (mutex)
1328                 sigflags |= (1 << (signo - 1));
1329         else
1330                 handle_hup(signo);
1331 }
1332
1333
1334 void
1335 signal_int(int signo)
1336 {
1337         if (mutex)
1338                 sigflags |= (1 << (signo - 1));
1339         else
1340                 handle_int(signo);
1341 }
1342
1343
1344 void
1345 handle_hup(int signo)
1346 {
1347         char *hup = NULL;               /* hup filename */
1348         char *s;
1349         char ed_hup[] = "ed.hup";
1350         int n;
1351
1352         if (!sigactive)
1353                 quit(1);
1354         sigflags &= ~(1 << (signo - 1));
1355         if (addr_last && write_file(ed_hup, "w", 1, addr_last) < 0 &&
1356             (s = getenv("HOME")) != NULL &&
1357             (n = strlen(s)) + 8 <= PATH_MAX &&  /* "ed.hup" + '/' */
1358             (hup = (char *) malloc(n + 10)) != NULL) {
1359                 strcpy(hup, s);
1360                 if (hup[n - 1] != '/')
1361                         hup[n] = '/', hup[n+1] = '\0';
1362                 strcat(hup, "ed.hup");
1363                 write_file(hup, "w", 1, addr_last);
1364         }
1365         quit(2);
1366 }
1367
1368
1369 void
1370 handle_int(int signo)
1371 {
1372         if (!sigactive)
1373                 quit(1);
1374         sigflags &= ~(1 << (signo - 1));
1375 #ifdef _POSIX_SOURCE
1376         siglongjmp(env, -1);
1377 #else
1378         longjmp(env, -1);
1379 #endif
1380 }
1381
1382
1383 int cols = 72;                          /* wrap column */
1384
1385 void
1386 handle_winch(int signo)
1387 {
1388         int save_errno = errno;
1389
1390         struct winsize ws;              /* window size structure */
1391
1392         sigflags &= ~(1 << (signo - 1));
1393         if (ioctl(0, TIOCGWINSZ, (char *) &ws) >= 0) {
1394                 if (ws.ws_row > 2) rows = ws.ws_row - 2;
1395                 if (ws.ws_col > 8) cols = ws.ws_col - 8;
1396         }
1397         errno = save_errno;
1398 }
1399
1400
1401 /* is_legal_filename: return a legal filename */
1402 int
1403 is_legal_filename(char *s)
1404 {
1405         if (red && (*s == '!' || !strcmp(s, "..") || strchr(s, '/'))) {
1406                 errmsg = "shell access restricted";
1407                 return 0;
1408         }
1409         return 1;
1410 }